Nonaqueous electrolyte battery containing a negative electrode of lithium-titanium composite oxide, battery pack and vehicle

Abstract

A nonaqueous electrolyte battery, containing a case and provided in the case, a positive electrode containing at least one selected from the group consisting of spinel type lithium-manganese-nickel composite oxide and lithium phosphate oxide having an olivine structure, a negative electrode and a nonaqueous electrolyte. The negative electrode comprises a lithium-titanium composite oxide, wherein a crystallite diameter of the lithium-titanium composite oxide is not larger than 6.9×10 2 Å. The lithium-titanium composite oxide comprises: rutile TiO 2 ; anatase TiO 2 ; Li 2 TiO 3 ; and a lithium titanate having a spinel structure. A main peak intensity relative to lithium titanate set at 100, as determined by X-ray diffractometry, of each of lithium titanate having a spinel structure, the rutile TiO 2 , the anatase TiO 2 and Li 2 TiO 3 is not larger than 7.

1 . A nonaqueous electrolyte battery, comprising:
 a case;   a positive electrode provided in the case;   a negative electrode provided in the case and comprising a lithium-titanium composite oxide comprising Na and K, wherein an amount of K is larger than an amount of Na; and   a nonaqueous electrolyte provided in the case.   
     
     
         2 . The battery according to  claim 1 , wherein a sum of the amount of Na and the amount of K is from 0.10% by weight to 3.04% by weight of the lithium-titanium composite oxide. 
     
     
         3 . The battery according to  claim 1 , wherein the lithium-titanium composite oxide comprises a crystallite diameter not larger than 6.9×10 2  Å, and in a X-ray diffractometry curve of the lithium-titanium composite oxide, none of a main peak intensity of a rutile type TiO 2 , a main peak intensity of an anatase type TiO 2  and a main peak intensity of Li 2 TiO 3  is larger than 7 when a main peak intensity of a lithium titanate having a spinel structure is set at 100. 
     
     
         4 . The battery according to  claim 3 , wherein the crystallite diameter of the lithium-titanium composite oxide is not smaller than 1.5×10 2  Å. 
     
     
         5 . The battery according to  claim 3 , wherein the crystallite diameter of the lithium-titanium composite oxide is not smaller than 2.6×10 2  Å. 
     
     
         6 . The battery according to  claim 3 , wherein none of the main peak intensity of the rutile type TiO 2 , the main peak intensity of the anatase type TiO 2  and the main peak intensity of Li 2 TiO 3  is larger than 3. 
     
     
         7 . The battery according to  claim 3 , wherein K and Na are positioned in a Li site of lithium titanate. 
     
     
         8 . The battery according to  claim 1 , wherein the nonaqueous electrolyte comprises at least two kinds of solvents selected from the group consisting of propylene carbonate, ethylene carbonate and γ-butyrolactone. 
     
     
         9 . The battery according to  claim 1 , wherein the nonaqueous electrolyte comprises γ-butyrolactone. 
     
     
         10 . The battery according to  claim 1 , wherein the nonaqueous electrolyte comprises at least three kinds of solvents selected from the group consisting of propylene carbonate, ethylene carbonate, y-butyrolactone, and vinylene carbonate. 
     
     
         11 . The battery according to  claim 1 , wherein the positive electrode comprises a compound represented by Li a Ni b Co c Mn d O 2 , where 0≦a≦1.1, 0.1≦b≦0.5, 0≦c≦0.9 and 0.1≦d≦0.5. 
     
     
         12 . The battery according to  claim 1 , wherein the lithium-titanium composite oxide comprises particles having an average particle diameter not larger than 1 μm. 
     
     
         13 . A battery pack comprising nonaqueous electrolyte batteries,
 each of the nonaqueous electrolyte batteries comprising:   a case;   a positive electrode provided in the case;   a negative electrode provided in the case comprising a lithium-titanium composite oxide comprising Na and K, wherein an amount of K is larger than an amount of Na; and   a nonaqueous electrolyte provided in the case.   
     
     
         14 . The battery pack according to  claim 13 , further comprising a protective circuit which detects a voltage of each of the nonaqueous electrolyte batteries. 
     
     
         15 . A vehicle comprising a battery pack defined in  claim 13 . 
     
     
         16 . A lithium-titanium composite oxide comprising Na and K, and an amount of K is larger than an amount of Na. 
     
     
         17 . The lithium-titanium composite oxide according to  claim 16 , wherein a sum of the amount of Na and the amount of K falls within a range of 0.10% by weight to 3.04% by weight. 
     
     
         18 . The lithium-titanium composite oxide according to  claim 16 , which comprises particles having an average particle diameter not larger than 1 μm. 
     
     
         19 . The lithium-titanium composite oxide according to  claim 16 , which comprises a crystallite diameter not larger than 6.9×10 2  Å, and in a X-ray diffractometry curve of the lithium-titanium composite oxide, none of a main peak intensity of a rutile type TiO 2 , a main peak intensity of an anatase type TiO 2  and a main peak intensity of Li 2 TiO 3  is larger than 7 when a main peak intensity of a lithium titanate having a spinel structure is set at 100. 
     
     
         20 . The lithium-titanium composite oxide according to  claim 19 , wherein K and Na are positioned in a Li site of lithium titanate.